O-ring



FIG. 1 is a top perspective view of our new design;

FIG. 2 is a bottom perspective view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a front elevational view thereof;

FIG. 6 is a rear elevational view thereof;

FIG. 7 is a right side elevational view thereof; and,

FIG. 8 is a left side elevational view. 

We claim the ornamental design for an o-ring, as shown and described. 